Dyneïne

Dyneïne, commonly spelled dynein in English, refers to a family of large ATPase motor proteins that move along microtubules toward the minus end. By hydrolyzing ATP, dyneins convert chemical energy into mechanical work to drive retrograde transport of organelles, vesicles, and RNA within cells, and to contribute to spindle dynamics during cell division and positioning of organelles such as the Golgi apparatus. A specialized subset, axonemal dyneins, powers the beating of cilia and flagella by causing microtubule doublets to slide.

Dyneins are multi-subunit complexes. The core motor is the dynein heavy chain, forming a dimer with a ring-shaped AAA+ ATPase motor domain and a microtubule-binding stalk. The tail binds cargo and links to accessory subunits. Cytoplasmic dynein-1 transports most intracellular cargo; dynein-2 drives retrograde intraflagellar transport in cilia. Axonemal dyneins occur as outer and inner arms on ciliary microtubules and power bending motion.

Dynein function is regulated by accessory factors, notably the dynactin complex and various adaptor proteins that link dynein to specific cargos. Regulatory proteins such as LIS1 and NudE (NudE-like) modulate dynein activity, particularly in neuronal cells, where dynein is crucial for nuclear migration and cortical development.

Mutations in dynein heavy chains and dynein-associated genes underlie several human diseases, including neurodevelopmental disorders and ciliopathies. For example, mutations in DYNC1H1 can cause cortical malformations, while defects in dynein-2 components are associated with skeletal ciliopathies. Ongoing research continues to reveal the diverse roles of dyneins in health and disease.